Александр

var data = {"test":1,"test2":[{"test3":3},{"test4":4}]};
var s = JSON.stringify(data,"\n",4);

{
    "test": 1,
    "test2": [
        {
            "test3": 3
        },
        {
            "test4": 4
        }
    ]
}

import json
data = json.loads("""[{'slot': -1, 'team': 2, 'time': 576.41, 'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'slot': -1, 'team': 2, 'time': 791.491, 'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 129,
  'slot': 6,
  'team': 3,
  'time': 1187.728,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 4,
  'slot': 4,
  'team': 2,
  'time': 1237.115,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 129,
  'slot': 6,
  'team': 3,
  'time': 1366.95,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'slot': -1, 'team': 2, 'time': 1621.088, 'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 130,
  'slot': 7,
  'team': 3,
  'time': 1655.347,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 132,
  'slot': 9,
  'team': 3,
  'time': 1686.872,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 2,
  'slot': 2,
  'team': 2,
  'time': 1751.123,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 4,
  'slot': 4,
  'team': 2,
  'time': 1780.849,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'slot': -1, 'team': 3, 'time': 1927.636, 'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 129,
  'slot': 6,
  'team': 3,
  'time': 2117.449,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'player_slot': 132,
  'slot': 9,
  'team': 3,
  'time': 2156.047,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'key': '512', 'time': 2178.992, 'type': 'CHAT_MESSAGE_BARRACKS_KILL'},
 {'player_slot': 4,
  'slot': 4,
  'team': 2,
  'time': 2326.829,
  'type': 'CHAT_MESSAGE_TOWER_KILL'},
 {'key': '2', 'time': 2333.384, 'type': 'CHAT_MESSAGE_BARRACKS_KILL'}]""".replace("'",'"'))
for i,e in enumerate(data):
	if e['type'] == 'CHAT_MESSAGE_BARRACKS_KILL':
		print(data[i-1])

SELECT u.id
FROM comments  c
LEFT JOIN users AS u ON u.id = c.user_id
WHERE c.created_at > to_timestamp('01.01.2019', 'DD.MM.YYYY') 
   AND c.created_at < to_timestamp('01.02.2019', 'DD.MM.YYYY')
GROUP BY u.id